Helical compressor and method of assembling the same

Abstract

In a helical compressor, a helical compression unit is accommodated in the case. The compression unit has a cylinder, a roller eccentrically disposed in the cylinder and a helical blade disposed between an inner surface of the cylinder and the roller for separately forming a plurality of compression chambers therebetween along an axial direction of the roller. A motor unit is accommodated in the case and is operatively connected to the helical compression unit through a rotating shaft for eccentrically rotating the roller in the cylinder through the rotating shaft. According to the rotation of the roller, compressive fluid sucked into a lower compression chamber is moved along an axial direction of the rotating shaft while being sequentially compressed. The helical compression unit and the motor unit is arranged so that the helical compression unit and the motor unit are partially overlapped to each other along the axial direction.

What is claimed is: 
     
       1. A method of assembling a helical compressor comprising the steps of: preparing a rotating shaft and a rotor;   inserting one end portion of the rotating shaft into the rotor thereby integrating the rotating shaft and rotor;   preparing a stator;   inserting the rotor having the rotating shaft through one end portion of an inner surface portion of the stator into the inner surface portion thereof;   preparing a compression unit having a cylinder, a rotating member eccentrically disposed in the cylinder and a helical blade disposed between an inner surface of the cylinder, the rotating member for separately forming a plurality of compression chambers therebetween along an axial direction of the rotating member and at least one bearing attached to one end portion of the compression unit for rotatably supporting the rotating shaft, said at least one bearing being adapted to close the one end portion thereof;   inserting the compression unit through the at least one bearing and the rotating member into the one end portion of the inner surface portion of the stator so that the compression unit and the stator are partially overlapped to each other along the axial direction of the rotating shaft;   preparing a case; and   attaching the stator having the rotor and the compression unit to an inner surface of the case.   
     
     
       2. A helical compressor comprising: a case;   a helical compression unit accommodated in the case and having a cylinder, a rotating member eccentrically disposed in the cylinder and a helical blade disposed between an inner surface of the cylinder and the rotating member for separately forming a plurality of compression chambers therebetween along an axial direction of the rotating member; and   a motor unit accommodated in the case and operatively connected to the helical compression unit through a rotating shaft for eccentrically rotating the rotating member in the cylinder through the rotating shaft so that compressive fluid sucked into one of the compression chambers is moved along the axial direction while being sequentially compressed,   wherein said helical compression unit and said motor unit are arranged so that the helical compression unit and said motor unit are partially overlapped to each other along the axial direction of the rotating shaft.   
     
     
       3. A helical compressor according to claim 2, wherein said compression unit has a main bearing and a sub bearing for rotatably supporting the rotating shaft, respectively, said main bearing and sub bearing being arranged along the axial direction such that the main bearing is close to the motor unit, and wherein said rotating shaft projects from the sub bearing toward a direction opposite to the motor unit side, further comprising a balancer attached to the projecting portion of the rotating shaft from the sub bearing. 
     
     
       4. A helical compressor according to claim 2, wherein said motor unit has a rotor joined to the rotating shaft and a stator disposed apart from an outer peripheral surface of the rotor for a predetermined gap and fitted in an inner surface of the case, and wherein said helical compression unit has one end portion facing to the rotor of the motor unit, said one end portion of the helical compression unit being inserted in an inner surface portion of the stator and so fitted to the inner surface portion of the stator as to be supported thereby. 
     
     
       5. A helical compressor according to claim 4, wherein said rotor is so disposed as to be shifted along the axial direction opposite to the compression unit side with respect to the stator, thereby forming a space between the rotor and the stator and wherein said one end portion of the helical compression unit is inserted and disposed in the formed space. 
     
     
       6. A helical compressor according to claim 4, wherein said one end portion of the helical compression unit supported to the inner surface of the stator is made of a non-magnetic material. 
     
     
       7. A helical compressor according to claim 4, wherein said one end portion of the helical compression unit supported to the inner surface of the stator is made of a non-conductive material. 
     
     
       8. A helical compressor according to claim 4, wherein said rotor comprises end rings at both ends thereof each of which has different and asymmetric thickness, respectively, said one thickness of the one end ring close to the compression unit as compared with the other end ring being smaller than the other thickness of the other end ring. 
     
     
       9. A helical compressor according to claim 4, further comprising a semi-hermetic cover having a gas hole and mounted onto one end surface of the stator opposite to the compression unit side so that a predetermined gap is provided between the cover and one end surface of the rotor opposite to the compression unit side for covering the one end surface thereof. 
     
     
       10. A helical compressor according to claim 4, wherein said helical compression unit has other end portion fixedly supported to the inner surface of the case so that the other end portion of the compression unit is closed by the case. 
     
     
       11. A helical compressor according to claim 4, wherein said helical compression unit has a main bearing for rotatably supporting the rotating shaft, and wherein said main bearing comprises a flange portion attached to an inner surface of one portion of the cylinder, said one portion including the one end portion of the cylinder and a bearing portion arranged so as to extend from the flange portion along the axial direction toward a direction opposite to the motor unit side, said rotating shaft being inserted into the flange portion and the bearing portion whereby the rotating shaft is rotatably supported. 
     
     
       12. A helical compressor according to claim 11, wherein said main bearing has an attachment portion projecting over the one end portion of the cylinder from the flange portion thereof and so inserted as to be fitted in the inner surface portion of the stator and the one end portion of the cylinder, said attachment portion being supported by the inner surface portion of the stator. 
     
     
       13. A helical compressor according to claim 11, wherein said rotor has a bore portion formed in one end portion thereof facing to the compression unit and wherein said flange portion has a boss portion for supporting the rotating shaft integrally extending from the flange portion along the axial direction toward the rotor, said boss portion being provided in the bore portion. 
     
     
       14. A helical compressor according to claim 4, wherein said helical compression unit is provided with a main bearing having an outer diameter for rotatably supporting the rotating shaft, said outer diameter being the same as an inner diameter of the cylinder, said main bearing is disposed inside one end portion of the cylinder, and wherein said one end portion of the cylinder facing to the rotor is inserted in the inner surface portion of the stator and so fitted to the inner surface portion of the stator as to be supported thereby. 
     
     
       15. A helical compressor according to claim 14, wherein said helical compression unit is provided with a sub bearing having an outer diameter for rotatably supporting the rotating shaft, said outer diameter being the same as the inner diameter of the cylinder, and wherein said sub bearing is disposed inside an other end portion of the cylinder. 
     
     
       16. A helical compressor according to claim 14, wherein said stator has a stepped and recessed portion formed at an end portion of the inner surface portion thereof facing to the one end portion of the cylinder and wherein said one end portion of the cylinder projects towards the stepped and recessed portion of the stator, said one end portion of the cylinder being fitted in the stepped and recessed portion of the stator so as to be supported thereby. 
     
     
       17. A helical compressor according to claim 14, wherein said stator has a coil end portion surrounding an outer surface of one portion of the cylinder, said one portion of the cylinder including the one end portion thereof, further comprising an insulating member interposed between the outer surface of the one portion of the cylinder and the coil end portion of the stator for electrically insulating the cylinder and the coil end portion of the stator. 
     
     
       18. A helical compressor according to claim 17, wherein said insulating member has an insulating film bonded to the outer surface of the one portion of the cylinder. 
     
     
       19. A helical compressor comprising: a case;   a helical compression unit accommodated in the case and having a cylinder, a rotating member eccentrically disposed in the cylinder and a helical blade disposed between an inner surface of the cylinder and the rotating member for separately forming a plurality of compression chambers therebetween along an axial direction of the rotating member;   a motor unit accommodated in the case and operatively connected to the helical compression unit through a rotating shaft for eccentrically rotating the rotating member in the cylinder through the rotating shaft so that compressive fluid sucked into one of the compression chambers is moved along the axial direction while being sequentially compressed; and   single bearing attached to one end portion of the compression unit for rotatably supporting the rotating shaft, said single bearing being adapted to close the one end portion thereof.   
     
     
       20. A helical compressor according to claim 19, wherein said rotating shaft has a crank portion for rotatably supporting rotating member and has at least one balancer integrally formed to the crank portion of the rotating shaft. 
     
     
       21. A helical compressor according to claim 19, wherein said rotating shaft has a crank portion for rotatably supporting the rotating member and has a first balancer integrally attached to one end portion of the rotating shaft opposite to the single bearing side with respect to the crank portion. 
     
     
       22. A helical compressor according to claim 21, wherein said motor unit has a rotor joined to the rotating shaft and a stator disposed apart from an outer peripheral surface of the rotor for a predetermined gap and fitted in an inner surface of the case, further comprising a second balancer attached to one end portion of the rotor close to the compression unit. 
     
     
       23. A helical compressor according to claim 19, wherein said one end portion of the compression unit is overlapped to the motor unit along the axial direction of the rotating shaft. 
     
     
       24. A helical compressor according to claim 23, wherein said single bearing is integrally formed to the one end portion of the cylinder. 
     
     
       25. A helical compressor according to claim 23, wherein said motor unit has a rotor joined to the rotating shaft and a stator disposed apart from an outer peripheral surface of the rotor for a predetermined gap and fitted in an inner surface of the case, said rotor has a bore portion formed at its center portion thereof between the rotor and the rotating shaft and wherein said single bearing has a boss portion integrally extending from the single bearing along the axial direction toward the rotor for supporting the rotating shaft, said boss portion being provided in the bore portion. 
     
     
       26. A helical compressor according to claim 23, wherein said compression unit has other end portion fixedly supported to an inner surface of the case so that the other end portion of the compression unit is closed by the case. 
     
     
       27. A helical compressor according to claim 23, wherein said motor unit has a rotor joined to the rotating shaft and a stator disposed apart from an outer peripheral surface of the rotor for a predetermined gap and fitted in an inner surface of the case, said stator has a coil end portion disposed at one end portion close to the compression unit and having an inner diameter, and wherein said cylinder integrating the single bearing has an outer diameter which is small as compared with the inner diameter of the coil end portion so that the cylinder integrating the single bearing is arranged in the coil end portion of the stator. 
     
     
       28. A helical compressor according to claim 27, further comprising an insulating member having one of an annular shape and a sleeved shape and interposed between an outer surface of a portion of the cylinder integrating the single bearing and the coil end portion of the stator, said portion of the cylinder being arranged in the coil end portion of the stator. 
     
     
       29. A helical compressor according to claim 27, further comprising a blade stopper mounted to the one end portion of the cylinder and adapted to be in contact with the blade for preventing the blade from moving along the axial direction. 
     
     
       30. A helical compressor according to claim 17, further comprising a blade stopper mounted to the single bearing and adapted to be in contact with the blade for preventing the blade from moving along the axial direction.